Locking Post Mount Mailbox | Large
Named Architectural Digest's Best Mailbox!
Adoorn’s lockable, weatherproof Post Mount Mailbox is built for mail delivery at the street or curb—roomy, secure, and made for everyday ease.
Overview
Features
Specifications
Designed To Deliver
FREE SHIPPING
No fees. Just fast delivery.
LARGE CAPACITY
Handles more than just mail.
WEATHERPROOF
Built to outlast the elements.
Designed To Deliver
LARGE CAPACITY
Handles more than just mail.
WEATHERPROOF
Built to outlast the elements.
FREE SHIPPING
No fees. Just fast delivery.
LARGE CAPACITY
Handles more than just mail.
WEATHERPROOF
Built to outlast the elements.
FREE SHIPPING
No fees. Just fast delivery.
Locking to Prevent Theft
Prevent identity theft, mail theft, and package theft. Roomy, secure, and made for everyday ease.
Extra Large, Oversize Capacity
Holds 7-14 days of mail and small packages—no cramming, no chaos. Just secure, spacious design made for how we get mail now.
Waterproof. Worry-Proof.
Made with heavy-duty galvanized steel, and a rust-fighting finish built to outlast rain, sun, and whatever else rolls in.
Receives Mail + Small Packages
Receives daily mail, poly-bag style mailers and multiple packages up to 16" x 10" x 2".
Need a Mailbox Without a Lock?
No key, no hassle, no problem.
Adoorn in Real Life
Swipe right to get a feel for size, shape, and styling in real spaces.
Made to Do More
Meets USPS Requirements
Engineered in accordance with all US Postal Service requirements for post mount locking mailboxes.
Receives Small Packages
Receives all types of mail + poly-bag style mailers + packages up to 16" x 10" x 2"
Heavy-Duty Galvanized Steel
Thick, weather-tough steel that resists rust and wear.
Secure Magnet Closure
A clean snap seals it shut—no slamming, no guessing.
Precision-Cut Foam Sealers
Foam lining locks out water and softens every close.
Anti-Pry Key Lock
Engineered anti-pry lock built to outsmart mail theft attempts.
Made To Do More
Secure Magnet Closure
A clean snap seals it shut—no slamming, no guessing.
Anti-Pry Key Lock
Engineered anti-pry lock built to outsmart mail theft attempts.
Precision-Cut Foam Sealers
Foam lining locks out water and softens every close.
Meets USPS Requirements
Heavy-Duty Galvanized Steel
Receives Small Packages
FEATURED IN
Find the right size for you.
If you get a lot of deliveries, multiple boxes a day or travel, get the large.
Find the right size for you.
Small holds 2-3 days of mail;
Large holds 7-14 days of mail.
How We Compare
Secure Lock Prevents Theft
Reinforced Weatherproof Sealing
Meets USPS Standards
Allows outgoing mail, meets size specs, passes weather-resistance testing and functionality testing.
Multiple Color Options
Receives What Type of Mail
Holds How Many Days of Mail
External Size Dimensions
Max Package Size
Post Mount | Small
available colors
Receives mail + polybag style packages
2–3 days of mail
12" H x 12" W x 18.5" D
Receives packages:
16" x 10" x 2"
Post Mount | Large
available colors
Receives mail + polybag style packages
7–14 days of mail
15.5" H x 12" W x 18.5" D
Receives packages:
16" x 10" x 2.5"
Competition
available colors
Receives mail + polybag style packages
1 day of mail
8.8" H x 7" W x 19" D
Receives packages:
19" x 6.75" x 4"
Compare Our Sizes
Secure Lock Prevents Theft
Reinforced Weatherproof Sealing
Meets USPS Standards
Multiple Color Options
Receives What Type of Mail
Holds How Many Days of Mail
External Mailbox Dimensions
Max Package Size
Small
mail + polybag
2–3 days
12" H
12" W
18.5" D
16" x 10" x 2"
Large
mail + polybag
7–14 days
15.5" H
12" W
18.5" D
16" x 10" x 2.5"
Details that Deliver
Locking to Prevent Theft
Prevent identity theft & mail theft with Adoorn’s locking mailboxes. They’re easily accessed by your mail carriers and delivery drivers yet keep out unwanted weather and sticky fingers.
Easy Outgoing Mail Clip
Keeps outgoing mail secure and in place. Raise the red flag to signal pickup—simple, smart functionality designed for easy, everyday use.
Mounting Pattern Made Simple
The pre-drilled base lines up with most standard posts. Just match the pattern for your post and you're ready to go.
Gear That Gets It Done
Every screw and washer’s in the box—just grab a wrench and Phillips head, then follow our step-by-step guide for a quick, secure install.
Should I buy a small or large size post mount mailbox?
The Post Mount | Small holds 2–3 days of mail and measures 12" H x 12" L x 18.5" D.
The Post Mount | Large holds 7–14 days of mail and measures 15.5" H x 12" L x 18.5" D.
The Small size is ideal if you retrieve mail every couple of days. If you're away frequently or take vacations, the Large size offers greater capacity and peace of mind.
Why locking? Do I really need it?
Recent research says 75% of people in the USA have had mail or package stolen in the last year (119M packages---that's a crazy number) & it is increasing every year.
Adoorn mailboxes are designed to protect against identity, mail & package theft. Theft is such a problem that the US Postal Service now has standards for locking mailboxes (which we adhere to of course!).
How does it work?
It works like the big blue USPS boxes.
Mail person simply opens the top door and places mail inside.
When the door shuts, mail falls into the secure location.
Retrieve your mail by using your key at your convenience.
Does this mailbox meet USPS requirements?
Yes! Our mailboxes abide by and follow all USPS regulations. Our installation instructions include guidelines for height and set back requirements at your curb. And, you can also include delivery instructions for deliveries to be placed in your mailbox.
What is the maximum size package that can fit in the mailbox?
The adoorn post mount mailboxes can receive mail, envelopes, polybag style packages and small rigid packages. The largest size rigid package that can fit inside the top opening is 16” x 10” x 2”.
If you're looking for a solution to receive package deliveries too, we recommend bundling a post mount mailbox with one of our Package Boxes.
How do I install the post mount mailbox?
It’s simple! For ease of installation and a guaranteed fit, we recommend purchasing one of our adoorn posts. Our post mount mailboxes can be installed into an adoorn post or most standard metal or wood mailbox posts. Installation hardware and easy-to-follow instructions come with the product. Our instructions include guidelines for height and set back requirements at your curb, but please contact your local post office if you have any questions!
Can I get a replacement key if I lose mine?
Each mailbox comes with 2 keys. And, each lock has a unique identification code to your specific mailbox. If you do lose your keys (we're sure you won't!), just send us an email to hello@adoorn.com to order replacements that match your lock's identification code.
Choose options
Customer Reviews
The mailbox was well packaged to insure there was no damage during shipping. Directions were clear and easy to follow which made installation stress free. It was nice that there was a reminder to register your key so that duplicates could be made if you misplaced the key. I would definitely recommend this product to others.
Very well made mailbox. I look forward to not having wet mail after rain or snow. I had to do a little decorating.
Loving this mailbox! Heavy duty and great colors!
Also love the locking ability. Didn’t want the typical black mailbox. Aegean sea is a gorgeous color…
